The present invention generally relates to window assemblies and, more particularly, to mechanisms for multipoint locking of a window sash to a window frame.
Window sashes are mounted in window frames and the window sashes either slide, rotate or pivot in the window frame between fully open and closed positions, or any position therebetween. Various locking devices have been provided in order to lock window sashes to their respective window frames when the window sashes are in the closed position. Namely, U.S. Pat. No. 5,118,145, issued to Tucker on Jun. 2, 1992, U.S. Pat. No. 5,791,700, issued on Aug. 11, 1998 to Biro, U.S. Pat. No. 5,829,802, issued on Nov. 3, 1998 to Anderson et al., and No. 5,927,768, issued on Jul. 27, 1999 to Dallmann et al., each describe locking systems for window sash/window frame assemblies that qualify as being multipoint. Multipoint locking mechanisms for window sash comprise at least two pairs of interacting members that interact to lock the window sash to the window frame in at least two different points. Having multiple points of locking between a window sash and a window frame ensures a secure locking therebetween. A multipoint lock is also desirable as it prevents warping of the window sash and maintains it flush with the window frame and the weather stripping thereof to assure a good seal. If the sash is warped, the multipoint lock will exert a force on the sash to straighten it in the window frame. The points of lock allow the window sash to exert a uniform pressure on the window frame, and therefore a tight seal between the window frame and the window sash is maintained.
It is known to provide multipoint locking wherein the window lock has ramped keepers secured to the window sash and cam rollers on a slider bar which is mounted to the window frame. The slider bar translates up and down on a side wall of the window frame in response to manual or motorized actuation of a handle. By displacing the slider bar upward, the cam rollers on the slider bar, which may also be cams or mushroom cams, each engage a ramped portion of a respective ramped keeper so as to lock the window sash to the window frame. It is pointed out that the window sash must be generally closed for the rollers to engage the ramped keepers, yet the ramped portions of the ramped keepers ensure that the window sash will lock even when the window sash is not completely closed. When the window sash is locked, the rollers of the slider bar rest against a flat surface of the ramped keepers and prevent the opening of the window sash.
It is a feature of the present invention to provide an improved multipoint locking mechanism for window sashes and wherein the keeper and cam are both wedges that provide increased surface engagement and a greater displacement span.
According to the above feature of the present invention, and from a broad aspect thereof, the present invention provides a cam wedge for a locking mechanism for locking a window sash in a closed position in a window frame. The locking mechanism is of the type having a slider portion translating longitudinally on a window frame in response to an actuation of a handle to engage at least two engagement members of the slider portion with corresponding keeper portions secured on the window sash for locking the window sash to the window frame. The cam wedge comprises a body having at least one ramped portion and a rest portion. The cam wedge is secured to the slider portion to be one of the at least two engagement members such that the at least one ramped portion abuts a corresponding keeper portion during a translation of the slider portion, and is guided by the corresponding keeper portion to abut the rest portion thereagainst to prevent a displacement of the window sash toward an open position thereof.
In accordance with a further broad aspect of the present invention, there is provided a multipoint locking mechanism for locking a window sash in a closed position in a window frame. The locking mechanism is of the type having a slider portion translating longitudinally in a window frame in response to an actuation of a handle to engage at least two engagement members of the slider portion with corresponding keeper portions in the window sash for locking the window sash to the window frame. At least one of the at least two engagement members is a cam wedge having at least one ramped portion and a rest portion. The cam wedge is positioned on the slider portion such that the at least one ramped portion abuts the corresponding keeper portion during a translation of the slider portion, and is guided by the corresponding keeper portion to abut the rest portion thereagainst to prevent a displacement of the window sash toward an open position thereof.